1. Field of the Invention
This invention relates to elastic fluid turbines and associated condensers, and more particularly to support configurations between such turbine and condenser.
2. Description of the Prior Art
Some of the stages in low pressure central station steam turbines typically operate at subatmospheric pressure and thus cause the turbine to be subjected to large atmospheric pressure forces which have commonly been balanced by the turbine's supporting structure. Subatmospheric pressure steam condensers for large central station applications are usually arranged beneath the low pressure turbine and its supporting structure and are connected to the low pressure turbine through a flexible expansion joint which permits relative motion between the turbine and condenser while preventing atmospheric leakage into the condenser. The condenser usually has its own support structure for bolstering weight of the condenser. Such condensers normally have a net atmospheric pressure force directed toward the turbine in the upward direction, but that force is greatly reduced by the weight of the condensate which collects in the bottom or hot-well of the condenser.
Until relatively recently, the support structure for central station turbines commonly consisted of reinforced concrete which also acted as a foundation for additional power generation apparatus. Since reinforced concrete was typically used for the turbine's pedestal, there was little cost savings incentive for reducing the turbine's atmospheric pressure force on its support structure. Recently, however, a new concept in central station power generation has evolved. The new concept includes launching large seagoing vessels containing power generation equipment such as turbines, condensers, etc. Support of such turbines necessitates use of relatively light-weight structures such as steel or other high strength structural components. As such, it has become important to minimize the size and weight of such supporting structures while maintaining the supportive capabilities necessary to bolster large central station turbines and associated apparatus.
A copending patent application by J. R. Dickey entitled "Condenser Vacuum Load Compensating System" is assigned to the assignee of the present invention, has a Ser. No. of 856,064, and discloses a configuration which can be useful in minimizing the turbine's support requirements. The aforementioned patent application utilizes stand pipes 76 and 80 to communicably couple its vapor chamber to its condensate chamber. Disadvantages of such configuration include: relatively high probability of falling condensate entering the vapor chamber between the stand pipes and surrounded structural members which must be drained away; increased material requirements for the stand pipes to permit communicable coupling between them and the structural members; and the pressure communicated from the condensate chamber to the vapor chamber is not equal to the pressure at the turbine exhaust neck which is the optimum.